The present invention relates to an information processing apparatus, an information processing method and a program storage medium. More specifically, the invention relates to an information processing apparatus, an information processing method and a program storage medium for use with a device that offers map information to users.
Maps commonly used in paper form generally emphasize topographical features as well as buildings and structures above the ground surface. These maps have been digitized recently for use on PCs and like equipment. The map data in digital form called digital maps (as in the ensuing description where appropriate) can be used by devices popularly known as navigation systems. Using the data, such devices can readily search for desired locations and for routes to preferred destinations.
The map data in digital form are most often recorded on mass storage media such as CD-ROMs (compact disc-read only memories) and DVDs (digital video discs). The entire map data recorded on such a storage medium are regarded either as a single file or as a continuous data stream. For that reason, the map data representing, say, Japan as a whole can amount to a huge file size.
The colossal, cumbersome map size may be circumvented illustratively by dividing map data into a plurality of files upon recording. One disadvantage of this method is that although the size of each divided file is small, a management file is needed to manage the resulting multiple files. The management file itself can become considerable in size.
When files are oversized, devices with modest processing capabilities or limited storage capacities are incapable of displaying maps based on the file or may give map displays but only after an interminable boot-up time. Where portable devices are used to download map data over a network for display, a large file size necessarily prolongs the download time.
If map data are managed by use of a plurality of files, only the necessary file needs to be downloaded in a relatively short time. However, it is also necessary to download a management file for handling the file in question, which can amount to a drawn-out download time after all.
Furthermore the digital maps, as in the case of maps in paper form, express primarily topographical features and buildings and structures on the ground surface. These topographically oriented, landmark-based digital maps were stored more or less appropriately by conventional map data storage methods. These methods are no longer suitable for map data that deal with, say, shop floor plans inside buildings and other detailed features.
The inability of the conventional methods to store floor-wise shop layout plans within buildings and structures as digital maps entails obvious disadvantages. With digital maps on display, it is impossible to change views from one floor to another within a building; to enlarge, reduce or scroll any given floor layout; or to look up underground shopping mall arrangements or other specifically desired details.